Fig. 2. Estimated evaporative water loss (EWL, i.e. the difference between water gain and cloacal fluid output) for sunbirds fed sucrose solutions of varying concentrations (0.07–2.5 mol l^–1), with (solid bars), or without (open bars), supplementary drinking water. EWL is expressed as a volume (A) and as a percentage of total water gain (B). Values are means ± 1 S.D. (N=7).